Abstract

Background

Hippocampal shrinkage is commonly reported in schizophrenia, but its role in the illness is still poorly understood. In particular, it is unclear how clinical and psychosocial variables relate to hippocampal volumes.

Aims

To investigate neuroanatomic differences in the hippocampus using three-dimensional (3D) computational image analysis.

Method

We used high-resolution magnetic resonance imaging and surface-based modelling to map the 3D profile of hippocampal differences in adults with schizophrenia (n = 67) and a healthy control group (n = 72). Manual tracings were used to create 3D parametric mesh models of the hippocampus. Regression models were used to relate diagnostic measures to maps of radial distance, and colour-coded maps were generated to show the profile of associations.

Results

There was no detectable difference between the schizophrenia and control groups in hippocampal radial distance. In the schizophrenia group, however, bilateral shape deflation was associated with greater illness severity (length of illness, positive and negative symptoms) and with poorer social functioning (educational level, quality of life and health status), which survived Bonferroni correction.

Conclusions

Illness severity and poor social functioning may be associated with hippocampal deflation in schizophrenia. As a structural sign of poor outcome, imaging measures might help to identify a subgroup of patients who may need specific treatment to resist hippocampal shrinkage, such as cognitive rehabilitation or physical exercise.

Footnotes

Funding

P.B. was partly supported by grants from the American Psychiatric Institute for Research and Education, the Italian Ministry for University and Research and the Italian Ministry of Health (IRCCS ‘E. Medea’). P.R., P.S. and P.M.T. were supported by National Institute of Health grants R01 EB008281, P41 RR013642, R01 AG020098 and R01 HD050735.